> Although in fairness this was a year ago on GPT 3.5 IIRC

GPT3.5 was impressive at the time, but today's SOTA (like GPT 5 Pro) are almost night-and-difference both in terms of just producing better code for wider range of languages (I mostly do Rust and Clojure, handles those fine now, was awful with 3.5) and more importantly, in terms of following your instructions in user/system prompts, so it's easier to get higher quality code from it now, as long as you can put into words what "higher quality code" means for you.